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preparation

...hydrated thorium phosphate as a gelatinous mass and then metathesizing the thorium phosphate to thorium hydroxide. Finally, the crude thorium hydroxide is dissolved in nitric acid to produce a
thorium nitrate-containing feed solution suitable for final purification by solvent extraction (
see below).

Aqueous solutions of highly purified
thorium nitrate, Th(NO
3)
4, are produced when thorium ores are processed. The nitrate is extensively used in the commercial production of gas mantles. Such mantles are made by impregnating cotton or synthetic fibres with a 25 to 50 percent solution of...